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81.
Objectives. To test the hypothesis that transgenic mouse models of prostate cancer could be useful for testing chemoprevention strategies by evaluating the effects of early castration on prostate carcinogenesis in TRAMP mice. Human prostate cancer, unlike other cancers, requires androgens for oncogenesis yet acquires partial androgen independence in the castrated milieu. This paradigm is the basis for an ongoing clinical trial using selective androgen deprivation for prostate cancer chemoprevention. However, preclinical correlates for hormonal prevention or other chemoprevention strategies of prostate cancer have not previously been demonstrated in autochthonous models of prostate carcinogenesis.Methods. Magnetic resonance imaging was used to longitudinally measure prostate growth in castrated and noncastrated TRAMP mice, and mice were prospectively examined for the onset of advanced, palpable prostate cancer. Modulation of androgen-responsive oncogene expression, as well as oncogene expression in refractory cancers, was evaluated by Western blot.Results. Early castration significantly reduced prostate tumor growth as measured by magnetic resonance imaging and improved cancer-free survival. Prevention of prostate cancer development in these mice was associated with durable suppression of androgen-responsive oncogene expression (T-antigen expression not detectable by Western blot); prostate cancers refractory to the hormonal prevention strategy demonstrated androgen-independent oncogene expression.Conclusions. These findings suggest that carcinogenesis related to androgen-responsive oncogene expression can be prevented in some cases by hormonal manipulation and that transgenic TRAMP mice are useful for the preclinical evaluation of hormonal and possibly other strategies of prostate cancer chemoprevention.  相似文献   
82.
Current methods of peripheral nerve repair are to directly suture cut nerve stumps, or to bridge large gaps with an autograft repair. Autograft-associated problems include donor site morbidity and limited supply. Many of the present limitations of nerve repair might be overcome by expanding the patients own Schwann cells in vitro, then combining the cells with other neuro-tropic and -trophic materials into an Artificial Nerve Graft (ANG) for bridging a nerve gap. In this 4.5 month experiment, a rat peroneal nerve model with a 10 mm gap was used to evaluate the effect of live Schwann cells on peripheral nerve regeneration. Nerve gaps were repaired with cellular ANGs containing live Schwann cell, dead Schwann cell, or mixed fibroblast/Schwann cell populations suspended in a collagen I matrix, and with sutured autografts or ANGs containing just collagen or medium. Regenerated nerves were evaluated by walking track analysis, qualitative and quantitative histology, and electrophysiology. Overall, the autograft was the best repair method, while the ANG containing live Schwann cells was statistically superior to other ANG repair methods. This study demonstrates that an ANG containing cultured syngeneic Schwann cells improves functional, histological, and electrophysiological parameters of peripheral nerve regeneration.  相似文献   
83.
A renal tumor developing in a patient receiving cyclophosphamide (Cytoxan) therapy for Wegener granulomatosis is reported. The tumor was similar histologically to the "immunoblastic" sarcoma that develops in renal allograft recipients as a complication of immunosuppressive therapy. This case report strengthens the cause and effect relationship between immunosuppressive drug usage and the subsequent development of neoplasia.  相似文献   
84.
The highly reproducible histochemical localization of glial fibrillary acidic protein (GFAP)? qualifies it as an important marker of astrocytes in both research and clinical applications. The primary objective of this study was to produce monoclonal antibodies having the advantage of invariant specificity, affinity, and titer to GFAP-specific epitopes of wide species distribution. We report here the characterization of four monoclonal antibodies that recognize the same or spatially close epitopes specific to GFAP. The epitope(s) detected has been phylogenetically conserved; human, bovine, ovine, canine, porcine, rabbit, guinea pig, rat, murine, and chicken brain homogenates all specifically absorb monoclonal antibody activity. Of importance to the routine application of these new anti-GFAP monoclonal antibodies is the demonstration here of the stability of the antigen-antibody interaction in normal, reactive, and neoplastic astrocytes of both rat and human origing following various methods of fixation.  相似文献   
85.
Natham B 《Obesity surgery》1992,2(3):217-218
Medieval medical views on obesity are presented from Avicenna's Canon of Medicine. Health risks associated with obesity were appreciated, including respiratory and cardiovascular problems, infertility and even sudden death.  相似文献   
86.
OBJECTIVE AND IMPORTANCE: Infiltration of the brachial plexus with anesthetics can provide relief of upper-extremity pain from invasive cancer. Because the analgesia is short-lived, however, repeated invasive treatments are necessary. We describe the implantation of a catheter reservoir system, in which anesthetic injections through a subcutaneous port resulted in anesthetic infiltration of the brachial plexus. CLINICAL PRESENTATION: A 47-year-old Hispanic man with squamous cell carcinoma of the larynx had undergone surgical resection, radiation treatment, and chemotherapy. Two years later, he had locally recurrent disease involving the brachial plexus, neck, and chest wall. The patient's pain was minimally responsive to narcotics, which also caused severe nausea and anorexia. TECHNIQUE: The brachial plexus was localized percutaneously with a needle electrode stimulator. Contrast injection under fluoroscopy confirmed entry into the plexus sheath. With use of the Seldinger technique, two Silastic catheters were placed within the brachial plexus and attached with a "Y" connector to a reservoir. The patient experienced complete relief of upper-extremity pain after a test injection with xylocaine. Thereafter, serial injections of bupivacaine with triamcinolone at 1-week intervals provided complete pain relief. After the treatments were initiated, the patient reported improved sleep and an improvement in his quality of life. CONCLUSION: A catheter reservoir system for brachial plexus analgesia can provide safe and effective analgesia for upper-extremity pain. This technique negates the need for repeated invasive procedures and avoids the complications of neurolysis.  相似文献   
87.
Whether fruit, vegetable, and antioxidant micronutrient consumption is associated with a reduction in breast cancer incidence remains unresolved. To address this issue, we analyzed data from a large population-based case-control study, with consideration given to whether the associations varied with menopausal status or with clinical characteristics of the cases' disease. Study participants completed a modified Block food frequency questionnaire, which included assessment of the frequency and portion sizes of 13 fruits and fruit juices and 16 vegetables and the use of multiple and single vitamin supplements. Statistical analyses were done on 1,463 cases and 1,500 controls. Among postmenopausal women, reduced odds ratios [OR; 95% confidence intervals (95% CI)] were noted for the highest fifth, as compared with the lowest fifth, of intake of any vegetables [0.63 (0.46-0.86); P for trend < 0.01] and leafy vegetables [0.66 (0.50-0.86); P for trend = 0.03] after controlling for age and energy intake. Adjusted ORs (95% CIs) were also decreased for postmenopausal breast cancer in relation to high intake of carotenoids, alpha-carotene, beta-carotene, lutein, and particularly lycopene [0.66 (0.48-0.90); P for trend = 0.03]. Inverse associations for fruits and vegetables were stronger for postmenopausal women with estrogen receptor (ER)+ tumors (OR, 0.65; 95% CI, 0.51-0.82) than ER- tumors (OR, 0.92; 95% CI, 0.64-1.32), but results were less consistent for micronutrients. No similarly reduced associations were observed among premenopausal women. ORs did not appreciably differ by in situ or invasive breast cancer or by whether cases had begun chemotherapy. Our results support an inverse association for fruit and vegetable intake among postmenopausal but not premenopausal breast cancer, which may be more pronounced among women with ER+ tumors.  相似文献   
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We report a case of an 80-year-old man with osteoblastic metastases from advanced carcinoma of the prostate presenting with a grand mal seizure resulting from severe hypocalcaemia. He had low serum phosphate and ionised calcium levels, elevated serum skeletal alkaline phosphatase and intact parathormone levels. 99mTc radioisotope bone scan revealed a "super bone scan" suggestive of osteomalacia. The serum 1, 25-dihydroxycholecalciferol level was unexpectedly elevated. The biochemical abnormalities persisted despite high dose calcium replacement, but improved with supraphysiological doses of 1,25 (OH)2 vitamin D3 (Rocaltrol) therapy. We hypothesise that the hypocalcaemia in this patient was due to vitamin D resistance secondary to a humoral factor secreted by the tumour.  相似文献   
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